Heating coil for carburetors



1;. SORENG. HEATING COIL FOR CARBURETORS.

KPPLICATION FILED JAN. 7. I918. I

Patented July 18, 1922-.

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YE. M. SORENG.

HEATING COIL FOR CARBURETORS'. APPLICATION FILED JAN. 7, 191B.

1 ,422,896, Patented July 18, 1922.

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WITNESSES.

UNITED STATES PATENT QFFHCE.

EDGAR M. SORENG, OF MILWAUKEE. WISCONSIN, ASSIGNOB, TO BRIGGS & STRATTON COMPANY, OF MILWAUKEE, WISCONSIN, A. CORPORATION OF WISCONSIN.

HEATING COIL FOR CABBURETORS.

Specification of Letters Patent.

Patented July is, 1922.

Application filed January 7, 1918. Serial No. 210,692.

T 0 all whom. it may 00nce1m:

Be it known that I, EDGAR M. SonnNo, a citizen of the United States, and resident of Milwaukee, Milwaukee County, VViscong sin, have invented new and useful Improvements in Heating Coils for Carburetors, of which the following is a description, reference being had to the accompanying drawings, which are a part of this Specification.

This invention has for its object to provide a heating coil for carburetors positioned on and movable with the throttle valve in the path of the spray of fuel from the carburetor suction nozzle, whereby, in the nearly closed position of the throttle valve, as for starting the engine, said heating coil willbe positioned across the stream of fuel from the nozzle to be most effective for heating the same, while in the open position of the throttle the heating coil will be in a position to be out of the way. where it will not ma terially afl ect the passageway through the intake manifold.

'It is a well recognized fact that a car burctor properly adjusted for ordinary running conditions is usually inefficient when an attempt is made to start a gas engine in cold weather. The liquid fuel being'cold is less volatile and consequently is not as easily taken up by the current of air.' Such particles asare carried along with the air are not in a finely divided, atomized state and do not readily vaporize but are apt to collect on the chilled walls of the intake manifold without reaching the cylinders. Various remedies have been proposed such as surrounding the intake manifold with a heating jacket and the placing of a heating coil in the float chamber, but these involve a considerable loss of time and are expensive to maintain and are not highly eflicient. 'It is, therefore, proposed by'the present'i nvention, to direct the stream of fuel immediately upon an electricallyheated coil-so as to heat and immediately vaporize only that portion ofthe fuel which is on, its way to the cylinders without a loss of heat due to an attempt to raise the temperature of a comparatively large volume of fuelflin the float chamber or a loss of heat by conduction of the metal parts, and so obtain a quick starting ofthe engine with a minimum expenditure of energy. 1 I

Another object of the invention is to mount the heating coil on the butterfly throttle valve and utilize the stem of the throttle valve as a conduit through which electrical connection is made therewith.

Another object of theinvention is to 0b: tam a greater efficiency by locating the heating coil in the confined space between the throttle valve and the fuel nozzle where the heat will be taken up by the vapor of fuel instead of being applied to a body of liquid fuel as when the heating coil is located in the float chamber.

Another object of the invention is to so locate the heating coil that it will be directly in the path of the streamof fuel from the nozzle and close to the nozzle where it will bemore effective in its action'than if located at a distance from the nozzle, as in the latter case the fuel vapor may condense along the cold walls of the intake manifold.

Another object of the invention is to perfect details of construction of a device of this character.

lVith the-above and other objects in View the invention consists in the carburetor heatmg coil, its parts and combinations of parts as herein claimed and all equivalents.

Eeferring to the accompanying drawings, in which like characters of reference indicate the same parts in different views:

Fig. 1 isa view of a'carburetor'partly sectioned to show the heating coil of this invention 7 V Fig. 2 is a detail view with the throttle valve stem sectioned; and,

' Fig. 3 is a view of. the throttlevalve with the heating coil thereon. I

s Fig. l is a sectional elevation of a modification; and y Fig. 5 is a detail View of the heating element' thereof.

In these drawings is shown a carburetor wh ch may be of any desired construction with an upwardly directed valve controlled fuel nozzle 10 supplying gasoline or other fuel from'a surrounding float chamber 11 to a central air passageway 12 containing a butterfly throttle valve 13 and having a flange it for coupling it to the intake manifold of a gas engine.

4 The butterfly valve 13 consists of the usual disk mounted on a stem 15 forming the trunnions therefor by which it is pivotally mounted in the openings or bearings in the I wall of the air passageway 12, one project- .ing end having the usual'operating lever 16 secured to it and controlled in any suitable manner for changingthe position of the throttle valve so as to more or less choke the air passageway and thus regulate the suction communicated to the carburetor from the engine and the quantity of fuel supplied to the engine.

T he throttle valve stem 15 is made hollow from its other end for more than half its length and within this bore is a tubular metal lining 17 surrounded by insulation 18 preventing its contact with the metal of the valve stem. A helical coil of suitable resistance wire 19 is mounted on the throttle valve in a plane parallel therewith and spaced a short distance therefrom, with its outer end soldered or otherwise electrically connected to the valve member, and its inner and passing through an elongated opening in the valve stem 15 and through an opening in the lining tube 17, and its surrounding insulation and then out of the end of the lining tube where it is bent to form a loop 20 or is otherwise formed with a suitable contact for engagement by a contact spring 21. which will maintain electrical connection with the resistance wire notwithstanding the movements of the throttle valve.

The contact spring 21 may be connected with a storage battery or other source of electrical energy through a suitable switch or other controlling means, and being in con-tact with the end of the heating coil 19 the current is conducted through said heating coil to its outer end where it is connected with the throttle valve to form a ground connection to complete the circuit with the battery, one terminal of which is presumed to be grounded. The insulation 18 protects the heating coil from short circuit, while the metal lining 17 protects the insulation from the heat of the wire passing therethrough In starting the engine the throttle is moved to the position shown in full lines in Fig. 1, and the heating coil switch is closed long enough to heat the charge and start the engine in its normal operation.

The heating coil 19 is on the underside of the throttle valve and in position, when the throttle valve is nearly closed, as for starting, to extend across the stream of fuel projected from the nozzle 10 so as to have the tiny globules of fuel brought into contact therewith and converted into vapor by its heat. As the heating coil is positioned to direct its heating influence upon the contents of the passageway 12 instead of upon the gasoline in the float chamber, or the metal of the intake manifold, there is much less loss of heat by conduction and radiation and consequently a better mixture of the air and gas is obtained and it is given a sufficiently high temperature to retain it in its gaseous state until it is ignited in the cylinders of the engine.

lVith the heating coil of this invention the globules of gasoline or other fuel are thrown directly upon the hot wire and are immediately vaporized on the principle that water is converted into steam in a flasher boiler. In other words, the fuel is atomized into a fine spray of small liquid globules in suspension by the action of the strong current of air passing the open end of the nozzle and is then projected against the hot wire by which the liquid globules are boiled to a gaseous vapor in condition to readily mix ith the hot air and be conducted with it to the cylinders of the engine where it arrives in proper condition for compression and ignition.

The location of the heating coil is such that it intercepts the current of fuel to ensure the heating and complete vaporization thereof, while permitting the current of air to pass on either side, the momentum of theglobules of liquid fuel carrying them straight ahead against the heating coil, while the air and the gas resulting from the action of the coil on the fuel are deflected and pass around the edges of the throttle valve.

This location of the heating coil on the throttle valve and in a plane parallel with the throttle valve, while presenting a maxi mum interception of the fuel stream in the closed position of the valve for starting, does not materially obstruct the passageway when the valve is open, for the heating coil swings with the valve and presents its edge of least resistance to the passage of a current of air and fuel in the open position of the throttle valve.

It is obvious that various details of construction shown and described in this exemplification of the invention are not essential and may be varied without departing from my invention, and I therefore desire it to be understood that this invention is not limited to any specific form or arrangement of parts except in so far as such limitations are specified in the claims.

Many of the features of advantage for the form of construction above described are contained in the modified form of the invention shown in Figs. 4: and 5 where the heating coil, instead of being mounted on the throttle valve, is mounted on a plug removably fitting in the wall of the carburetor passageway.

A screw plug 22 is threaded through the wall of the passageway 12 of the carburetor 11 between the fuel nozzle 10 and the throttle valve 13. A rubber gasket is preferably fitted between the head of the plug and the wall of the passageway to make a tight connection.

An insulating tube 28 passes through the central bore of the plug 22 with its shoulder bearing against the inner end of said plug and its end terminating within an insulating washer 24 bearing against the head of the plug. A metal rod 25 passes through the insulating tube 23 with a shoulder 26 hearing against the shoulder of said insulating tube and with its outer end screw threaded with a thumb nut 27 turned thereon against a terminal clip 28, which in turn bears against a metal washer 29, thus affording electrical connection for the rod and insulation separating it from the screw plug. The inner end of the rod 25 continues beyond the shoulder 26 with its end flattened and having a screw 30 threaded therein, and a heating coil 31 surrounds said end of the metal rod with one end attached thereto by means of the screw 30 and the other end, after passing a convolution around the head of the insulating tube 23 to hold the convolution of the coil away from the rod, is soldered to the end of the screw plug 22. The diameter of the helical heating coil 31 is such that it will readily pass through the opening into which the screw plug 22 is threaded, and the entire device as a unit maybe readily placed in assembled position in the carburetor or may be removed therefrom for repair.

With the battery connection made with the terminal clip 28, the heating coil 31 will act in much the same manner asthe heating coil 19 of the other construction when the switch is closed, serving to heat the chamber within the passageway 12 be-' neath the closed throttle valve and intercepting the current of fuel' from the nozzle 10 on its way to the throttle valve and converting it into a vapor or gaseous state in which it will remain until it is exploded in the cylinder of the engine.

What I claim as new and desire to secure by Letters Patent is:

1. In a carburetor, a throttle valve, and a helix of resistance wire secured on one face thereof forming an exposed electric heating coil.

2. A heater for carburetors, comprising an exposed coil of resistance wire secured to and spaced from the throttle valve.

3. In a carburetor having a passageway and a fuel nozzle, an exposed electric heating coil pivotally mounted to swing across the passageway in the path of the fuel spray from the nozzle.

4. In a carburetor, a throttle valve, a helix of bare resistance wire mounted on the throttle valve in a plane parallel therewith 'and close thereto, and means for establishing electrical connection with the heating coil.

5. In a carburetor having a passageway and a fuel nozzle, a throttle valve capable of movement to a position across the passageway, and an electric heating coil comprising a helix of bare resistance wire secured to the throttle valve in a plane approximately parallel therewith and close thereto and adapted to extend across the path of the fuel spray from the nozzle.

In testimony whereof, I affix my signature, in presence of two witnesses.

EDGAR M. S'ORENG. Witnesses:

MARY E. SMITH, R. S. O. OALDWELL. 

